Genetics Midterm - Summer Class

A strategy to induce random indels in a target sequence might use __________.

NHEJ to litigate fragments

In which phase of the bacterial cell cycle do the cells grow most quickly?

log

What is a plaque composed of?

lysed bacteria, phage, and agar

What is the process by which a temperate bacteriophage infects a bacterial cell and subsequently integrates its chromosome into the bacterial chromosome?

lysogeny

Describe the molecular and transmission characteristics of Leber's hereditary optic neuropathy (LHON).

maternal inheritance, which includes mtDNA lesions

List three criteria indicating that a human disorder may be attributable to genetically altered mitochondria.

maternal rather than Mendelian inheritance pattern, deficiency in some bioenergetic functions of mitochondria, documentation of a specific genetic mutation

Which of the following are the areas where chromotids intertwine during meiosis? A) synapsis B) chiasma C) tetrad D) bivalent E) nondisjuction

B) chiasma

Which protein directly holds the chromatid arms together prior to anaphase of mitosis? A) shugoshin B) cohesin C) separase D) middle lamella E) histone

B) cohesin

At what stage of cell division do sister chromatids go to opposite poles? A) mitotic anaphase and anaphase of meiosis I B) mitotic anaphase and anaphase of meiosis II C) anaphase of meiosis I only D) mitotic anaphase only E) when they don't get along

B) mitotic anaphase and anaphase of meiosis II

The number of possible gametes, each with different chromosome compositions is 2, where n equals ________. A) the diploid number B) the haploid number C) the number of offspring D) the number of genes E) the number of alleles

B) the haploid number

In what way do chloroplast mutations influence phenotype?

Chloroplast mutations affect the production of the photosynthetic machinery and/or capabilities of plants, thus influencing the production and utilization of sugars and related energy-rich molecules.

The horse (Equus caballus) has 32 pairs of chromosomes, whereas the donkey (Equus asinus) has 31 pairs of chromosomes. How many chromosomes would be expected in the somatic tissue of a mule, which is a hybrid of these two animals? A) 63 B) 64 C) 62 D) 60 E) 126

A) 63

If an F2 generation from a F1 self-cross always yields offspring in a 3:1 phenotypic ratio with of the following P crosses could have occurred? A) AA x aa B) AA x AA C) aa x aa D) Aa x AA E) aa x Aa

A) AA x aa

___________________ is viewed as a major cause of aneuploidy.

Nondisjunction

Although the most frequent forms of Down syndrome are caused by a random error, nondisjunction of chromosome 21, Down syndrome occasionally runs in families. The cause of this form of familial Down syndrome is ___________________.

a translocation between chromosome 21 and a member of the D chromosome group

What is a bacteriophage?

a virus that has a bacterium as its host

Alleles are the alternative forms of the same gene. a) True b) False

a) True

Under what condition may a human female have the XY sex chromosome complement?

This female would have one complete X chromosome and a Y chromosome that lacks SRY.

Assuming complete dominance, a 3:1 phenotypic ratio is expected from a monohybrid self-cross. a) True b) False

a) True

Bacteria protect themselves from viral infection by producing restriction enzymes. a) True b) False

a) True

In an autosomal recessive disorder, if one parent is homozygous recessive and the other parent is homozygous dominant, then all children will be unaffected heterozygotes. a) True b) False

a) True

In spermatogenesis, cytoplasm is equally partitioned between haploid sperm cells, whereas in oogenesis one egg gets most of the cytoplasm and the other gets very little. a) True b) False

a) True

Phenotypes are often the combined result of genetics and the environment in which the genes are expressed. a) True b) False

a) True

Alleles that are masked by an epistatic locus are said to be ________ to the genes at that locus. a) hypostatic b) complementary c) auxotrophic d) functional e) conditional

a) hypostatic

Individuals have been identified who have two different karyotypes, such as 45,X/46, XY or 45, X/46, XX. Such individuals are called _______________.

mosaics

X-linked genes in female mammals often demonstrate ______________.

phenotypic mosaicism -Mosaicism is characterized by genetic or functional difference of two or more cell lines in one individual from one zygote.

Haploinsuffieciency refers to...

the condition in which a single chromosome is insufficient to sustain life

A genomic condition that may be responsible for some forms of fragile X syndrome, as well as Huntington's disease, involves _____________________.

various lengths of trinucleotide repeats

How many Barr bodies would one expect to see in cells of Turner syndrome females and Klinefelter syndrome males?

zero and one

Tightly curled hair is caused by a dominant gene in humans. If a heterozygous curly-haired person marries a person with straight hair; what fraction of their offspring would be expected to have straight hair? a) ½ straight b) ¼ curly c) 100% straight d) ¾ curly e) None

a) ½ straight

Describing bacterial conjugation, which of the following matings is most likely to result in a change from F- to F+?

donor F+ recipient F-

............ lead to genetic variations a) Mutation b) Crossing over c) Independent assortment d) A and B e) A, B and C

e) A, B and C

The largest category of proteins is a) transport proteins b) histone proteins c) structural proteins d) antibodies e) enzymes

e) enzymes

Noninvasive prenatal genetic diagnosis is sometimes preferred to amniocentesis because....

it requires only a blood draw from the mother

mechanisms of adaptive immunity include _____________________.

learning from past exposures

Direction of shell coiling in the snail Limnaea peregra is conditioned by a form of extrachromosomal inheritance known as ________.

maternal effect

Direction of shell coiling in the snail Lymnaea peregra is conditioned by a form of extrachromosomal inheritance known as __________________.

maternal effect

List two classes of extrachromosomal inheritance and give an example of each.

maternal effect, pigmentation in Ephestia kuehniella; organelle heredity, variegation in Mirabilis jalapa

Which of the following organelles are involved in the general category of organelle heredity?

mitochondria and chloroplasts

One explanation for organelle inheritance is that ________.

mitochondria and chloroplasts have DNA that is subject to mutation

One explanation for organelle inheritance of disease phenotypes is that _________________.

mitochondria and chloroplasts have DNA that is subject to mutation.

During meiosis, chromosome number reduction takes place in _________. A) anaphase II B) anaphase I C) metaphase I D) prophase I E) telophase II

B) anaphase I

Forms of inheritance that do not follow typical Mendelian patterns and that appear to be more influenced by the parent contributing the most cytoplasm to the embryo are grouped under the general heading of ________.

extrachromosomal inheritance

The promiscuity of the CRISPR-Cas9 system likely benefits bacteria by _______________.

facilitating defense against new viral attacks

In Neurospora crassa, a mutation called poky (phenotype is slow in growth) is passed down cytoplasmically. Which cross below is not consistent with this type of in heritance?

female wild type × male wild type yields half poky

cpDNA: Chloroplast DNA

- Genes encode products involved in photosynthesis and translation

A gene can have maximum two alleles. a) True b) False

b) False

Myoclonic epilepsy and ragged-red fiber disease

- Pattern of inheritance consistent with maternal transmission - Lack of muscular coordination - "Ragged-red" skeletal muscle fibers

Maternal effect (maternal influence)

- Offspring's phenotype is under control of nuclear gene products present in egg - Nuclear genes of female gamete transcribed; genetic products accumulate in egg's cytoplasm - Products distributed among newly formed cells, influencing patterns/traits established early in development

The inheritance of the petite phenotype in Saccharomyces cerevisiae is complicated by an interaction of mitochondrial and nuclear genes. What are four true statements about petites in S. cerevisiae?

- Both nuclear and cytoplasmic (mitochondrial) genes contribute to the petite phenotype in some cases - The three categories of petites are segregational, neutral, and suppressive -Neutral petites, when crossed to wildtype, yield wild-type mitochondrial function - Segregational petites are characterized by mutations in the nuclear genome

mtDNA: Mitochondrial DNA

- Exists in eukaryotes as double-stranded circular DNA - Smaller than DNA in chloroplasts

What is the criteria for human disorder to be attributed to mtDNA?

- Inheritance must exhibit maternal inheritance pattern - Disorder must reflect deficiency in bioenergetic function of organelle - Must have mutation in one or more mitochondrial gene

What are three disorders that arise from mtDNA?

- MERRF (myoclonic epilepsy and ragged-red fiber disease) - LHON (Leber's hereditary optic neuropathy) - KSS (Kearns-Sayre syndrome)

What is the endosymbiotic theory?

- Mitochondria and chloroplasts (organelles) arose independently 2 billion years ago from free-living bacteria - Organelles possessed attributes of aerobic respiration and photosynthesis, respectively Main points of endosymbiotic theory - Bacteria were engulfed by larger eukaryotic cells - Beneficial symbiotic relationship developed - Bacteria lost ability to function autonomously - Eukaryotic cells gained oxidative respiration and photosynthesis

What is a suppressive mutation in Saccharomyces cerevisiae (yeast)?

- Mutant and wild type cross gives diploid zygotes - Express petite phenotype

Why is mtDNA susceptible to mutations?

- No structural protection from histones - DNA repair mechanism limited - High concentrations of ROS (reactive oxygen species) generated by cell respiration ROS is toxic—damages organelle contents (proteins, lipids, mtDNA)

What are three varieties in extranuclear inheritance?

- Organelle heredity - Infectious heredity - Maternal effect

How does Maternal effect occur in Drosophila?

- Protein products of genes function to activate other genes; cascade effect of gene activity - Genes products illustrating maternal effect synthesized by developing egg and stored in oocyte - Upon fertilization, products specify molecular gradients for organization in zygote

Extranuclear inheritance

- Transmission of genetic information to offspring through cytoplasm not nucleus - Usually from one parent

Heteroplasmy

- Variation in genetic content of organelles - Zygote receives large number of organelles through egg - Mutation in one or few will be diluted out by many mitochondria that lack mutation and function normally - Adult cells have variable mixture of normal and abnormal organelles

organelle heredity

-One variety of extranuclear inheritance -DNA contained in mitochondria or chloroplasts determines certain phenotypic characteristics of offspring - Inheritance of chloroplast or mitochondrial traits often determined by phenotype of ovule source

Maternal Effect

-Variation of extranuclear inheritance - Nuclear gene products are stored in egg, then transmitted through ooplasm to offspring - Gene products in ovule distributed to embryo cells influence phenotype

Infectious heredity

-Variation of extranuclear inheritance -Results from symbiotic or parasitic association with microorganism -Inherited phenotype affected by microbe in host's cytoplasm

What are three potential consequences of a copy number variation?

-higher protein levels of specific genes -phenotypic consequences leading to enhanced ability to fight infection -loss of function at multiple loci

if interference is complete, what is the frequency of double crossovers?

0

Given that a human normally contains 46 chromosomes, give the chromosome number for each of the following conditions: 1. Turner syndrome (female, no Barr bodies) 2. Klinefelter syndrome (male, one Barr body) 3. Triploid 4. Down syndrome (trisomic) 5. Trisomy 13

1. 45 2. 47, XXY 3. 47, 2n + 1 4. 3 chromosome 21 5. 3 chromosome 13

Trisomy 21 or Down syndrome occurs when there is a normal diploid chromosomal complement of 46 chromosomes plus one (extra) chromosome #21. Such individuals therefore have 47 chromosomes. Assume that a mating occurs between a female with Down syndrome and a normal 46-chromosome male. What proportion of the offspring would be expected to have Down syndrome? Justify your answer.

1/2 of the offspring would be expected to have down syndrome

Assume that an organism has a haploid chromosome number of 7. There would be ______________ chromosomes in a monoploid individual of that species

14

Assume that the genes for tan body and bare wings are 15 map units apart on chromosome II in Drosophila. Assume also that a tan-bodied, bare-winged female was mated to a wild-type male and that the resulting F1 phenotypically wild-type females were mated to tan-bodied, bare-winged males. Of 1000 offspring, what would be the expected phenotypes, and in what numbers would they be expected?

15 map units apart means 15% of the offspring are products of recombination There are 1000 offspring 15% of the offspring are products of recombination = 150 85 % of the offspring are parental = 850 So out of 1000 offspring wild type 425 tan bare 425 tan 75 bare 75

Assume that an organism has a diploid chromosome number of 14. There would be _____________ chromosomes in a tetraploid.

28 (because it's asking for chromosomes not chromatids)

Jacob's syndrome in humans, which is manifested by a higher than average stature and potential behavioral problems, is caused by which chromosomal condition?

47, XYY

Klinefelter and Turner syndromes have how many chromosomes, respectively?

47,45

Assume that two genes are 80 map units apart on chromosome II of Drosophila and that a cross is made between a doubly heterozygous female and a homozygous recessive male. What maximum percent recombination would be expected in the offspring of this type of cross?

50%

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is inherited as an X-linked recessive gene in humans. A normal woman whose father suffered from G6PD marries a normal man. What percentage of their sons are expected to be G6PD?

50%

Assume that one counted 67 plaques on a bacterial plate where 0.1 ml of a 10^-5 dilution of phage was added to bacterial culture. What is the initial concentration of the undiluted phage?

6.7 x 10^7 pfu/ml (pfu=plaque-forming units) In initial concentration of undiluted phage (PFU/ml) = Number of colonies/ dilution * volume of diluted sample added to the plate = 67 * 10^5 = 67 x 10^5?????? look in book get help

What experiment led to the identification of the DSCR (Down Syndrome Critical Region) region?

A mouse model was developed trisomic for the DSCR

The ant, Myrmecia pilosula, is found in Australia and is named bulldog because of its aggressive behavior. It is particularly interesting because it carries all its genetic information in a single pair of chromosomes. In other words, 2n = 2. (Males are haploid and have just one chromosome.) Which of the following figures would most likely represent a correct configuration of chromosomes in a metaphase I cell of a female?A) Cell with two X sister chromatids horizontalB)Cell with one X sister chromatidsC) Cell with two X sister chromatids verticalD) Cell with two chromosomesE) Cell with four chromosomes

A) Cell with two X sister chromatids horizontal

Which of the following is true about the second meiotic division?A) Sister chromatids disjoin and are pulled to opposite polesB) Homologous chromosomes are pulled apart resulting in dyads at each poleC) nondisjuction would lead to extra bivalents formingD) Synapsis occurs in the second meiotic divisionE) the products are four identical gametes

A) Sister chromatids disjoin and are pulled to opposite poles

What is independent assortment? A) during gamete formation, a pair of unit factors segregates randomly from another pair of unit factors B)Fertilization is random C) During gamete formation, allele pairs are separated to form haploid gametes D) Genes lie on chromosomes E) Chromosomes can swap information during meiosis

A) during gamete formation, a pair of unit factors segregates randomly from another pair of unit factors

Living organisms are categorized into two major groups based on the presence or absence of a nucleus. What group is defined by the presence of a nucleus? A) eukaryotic organisms B) virus C) eubacterium D) archaea E) bacteriophage

A) eukaryotic organisms

When performing a dihybrid cross for the traits round/wrinkled and yellow/green, which of the following results best demonstrates that the unit factors from each trait was assorting independently?A) finding a 3:1 ration of round; wrinkled and a 3:1 ratio of yellow; green in the F2 generationB) the 9:3:3:1 ratio i the F2 generationC) finding the Punnett square and branched diagram methods yielded the same resultsD) finding only two visible traits in the F1 generation, but four visible traits among the F2offspringE) finding that round is dominant to wrinkled and yellow is dominant to green

A) finding a 3:1 ration of round; wrinkled and a 3:1 ratio of yellow; green in the F2 generation

Migration of chromosomes is made possible by the binding of the spindle to the _________. A) kinetochore B) telomere C) centriole D) equatorial plate E) centrosome

A) kinetochore

Which of the following is not a true statement about mitochondria? A) the mitochondria genome is contained in the nucleus B) the mitochondria duplicate themselves C) the mitochondria transcribe and translate their own genetic information D) mitochondria are found in plants and animals E) mitochondria are sites for cellular respiration

A) the mitochondria genome is contained in the nucleus

Mendel crossed two pea plants with round seeds. All seeds of the offspring were round. He then crossed with a plants with round seeds to a plant with wrinkled seeds and all offspring had wrinkled seeds. Which of the following is true? A) wrinkled is dominant B) the trait does not breed true C) the plants he used were not true breeding D) a mutation occured E) round is dominant

A) wrinkled is dominant

What is the difference between incomplete dominance and codominance?

An example of codominance is the roan cow which has both red hairs and white hairs. In incomplete dominance a heterozygous individual blends the two traits. An example of incomplete dominance is the pink snapdragon, which receives a red allele and white allele.

In an organism with 52 chromosomes, how many chromatids would be expected in each cell after the second meiotic division? A) 52 B) 26 C) 13 D) 104 E) 208

B) 26 52/2 and splits into 26 chromosomes each in anaphase I, then in anaphase II 26 chromosomes splits again (26/2+13) into 13 chromosomes. However, there are 2 chromatids per 1 chromosome so if we have 13 chromosomes we will have (13x2=26) 26 chromatids!

How do mitochondria and chloroplasts determine phenotypes? Which characteristics of mitochondria and chloroplasts allow such phenotypes to be inherited? Provide specific examples to illustrate your response.

Both mitochondria and chloroplasts possess DNA, which directs the synthesis of proteins. These proteins influence mitochondrial structure and function and, thus, influence the phenotype. Mitochondria are involved in energy conversions in cells (petite strains in yeast); chloroplasts are involved in photosynthesis as well as leaf coloration (iojap in maize).

The inheritance of the petite phenotype in yeast is complicated by an interaction of mitochondrial and nuclear genes. What are these complications? Which three categories of petites are commonly described?

Both nuclear and cytoplasmic (mitochondrial) genes contribute to the petite phenotype in some cases. The three categories of petites are segregational, neutral, and suppressive.

What signifigant genetic function occurs in the S phase of the cell cycle? A) cytokinesis B)karyokinesis C) DNA synthesis D) chromosome condensation E) centromere division

C) DNA synthesis

If a typical somatic cell has 64 chromosomes, how many chromosomes are expected in each gamete of that organism A) 8 B) 16 C) 32 D) 64 E) 128

C) 32 meiosis drops the chromosome number 64/2= 32/2= 16 BUT

Under what conditions does one expect a 1:1:1:1 ratio? A) AaBb x AaBb B) AABB x aabb C) AAbb x aaBB D) Aabb x AABB

C) AAbb x aaBB

What is segregation? A) during gamete formation, segregating pairs of unit factors assort independently of each other B) Fertilization is random C) During gamete formation, allele pairs are separated to form haploid gametes D) genes lie on chromosomes E) chromosomes can swap information during meiosis

C) During gamete formation, allele pairs are separated to form haploid gametes

Which of the following is true about sex determining chromosomes? A) They are independent during meiosis B) they do not participate in meiosis C) They act like homologous chromosomes during meiosis so each gamete will get one sex chromosome D) They have the same gene configuration and same loci E) They are always metacentric

C) They act like homologous chromosomes during meiosis so each gamete will get one sex chromosome

A certain type of congenital deafness in humans is caused by a rare autosomal dominant gene. In a mating involving a deaf man and a deaf woman, could all the children have normal hearing? A) No, because it is dominant. Children always get the dominant alleles. B) No, because children favor their parents C) Yes, assuming that the parents are heterozygotes (because the gene is rare), it is possible that all the children could have normal hearing D) Yes, because traits assort independently E) Yes, because it must be recessive if it's rare

C) Yes, assuming that the parents are heterozygotes (because the gene is rare), it is possible that all the children could have normal hearing

A cross between two individuals with different phenotypes that resulted in approximately 50% of each type of offspring would indicate the cross was _________. A) true breeding dominant to recessive B) a heterozygous dominant crossed to a heterozygous recessive C) a heterozygous dominant crossed to a homozygous recessive D) a homozygous recessive crossed with a heterozygous recessive E) true dominant to a heterozygous dominant

C) a heterozygous dominant crossed to a homozygous recessive

Assuming no crossing over between a gene in question and the centromere, when do alleles segregate during meiosis? A) prophase II B) prophase I C) anaphase I D) interphase E) anaphase II

C) anaphase I

For which of the following questions would you use the sum law? A) determining the chance of pulling an ace from a deck of cards B) determining the chance of having a baby girl C) determining the chance of pulling either a club or a heart from a deck of cards D) determining the chance of having a tall plant with purple flowers E) determining the chance of rolling a 5 on a six-sided die

C) determining the chance of pulling either a club or a heart from a deck of cards

What meiotic process, relative to the number of chromosomes of a given species accounts for a signifigant amount of genetic variation A) trivalent formation B) formation of the meiotic spindle during chromosome segeration C)independent assortment of chromosomes D) bivalent formation E) pairing of homologous chromosomes

C)independent assortment of chromosomes

Assume that a cross is made between AaBb and aabb plants and that the offspring occur in the following numbers: 106 AaBb, 48 Aabb, 52 aaBb, 94 aabb. These results are consistent with which scenario described? a. It is impossible to tell. b. In the AaBb parent, each homolog has one dominant allele and the recessive allele on the other. c. In the AaBb parent, the dominant alleles are on one homolog and the recessive alleles are on the other. d. The genes are unlinked e. There is a very high coefficient of coincidence

C. In the AaBb parent, the dominant alleles are on one homolog and the recessive alleles are on the other.

What is a great model organism for organelle heredity?

Chlamydomonas (unicellular green alga) - Excellent model system for studying organelle heredity (plastid inheritance) - Single large chloroplast with 75 copies of circular double-stranded DNA molecule

What is crossing over?

Crossover usually occurs when matching regions on matching chromosomes break and then reconnect to the other chromosome.

______________________ have lost, through ______________________, the ability to grow on minimal medium

auxotrophs; mutation

A recessive allele in dogs causes white spots. If two solid colored dogs are mated and produce a spotted offspring, what is the percentage chance their next puppy would be solid colored? A) 25% B) 50% C) about 66% D) 75% E) about 90%

D) 75%

How many kinds of gametes will be expected from an individual with the genotype PpCcTTRr? A) 16 B) 2 C) 4 D) 8 E) 1

D) 8 2x2x1x2 = 8

Which of the following terms defines a chromosome in which the centromere is near one end, but not at the end of a chromosome? A) acentric (not a thing) B)submetacentric C) metacentric D) acrocentric E) telocentric

D) acrocentric

Which of the following is incorrect? A) a locus is a gene site on a chromosome B)an allele is an alternate form of the same gene C) sex chromosomes are not strictly homologous D) homologous chromosomes contain identical genetic information E) a karyotype is generated from a metaphase spread

D) homologous chromosomes contain identical genetic information

What is the outcome of synapsis, a significant event in meiosis?A) side-by-side alignment of non-homologous chromosomesB) dyad formationC) monad movement to opposite polesD) side-by-side alignment of homologous chromosomeE) chiasma segregation

D) side-by-side alignment of homologous chromosome

Organized by the centrioles, what structures are important in the movement of chromosomes during cell division?A) mitochondriaB) chloroplastsC) cell wallsD) spindle fibersE) centromeres

D) spindle fibers

Mendel utilized the garden pea for his studies based on features that include all but ________. A) Can generate a large number of progeny B) reaches maturity in a single season C)Being able to hybridize artifically D)Has visible features with a wide spectrum of intermediates E)Easy to grow

D)Has visible features with a wide spectrum of intermediates

An advantage of base editor technology is that ________________________.

DNA is not cut so there are no indels? or specific basic sequences are edited, leading to a more specific product

Kearns-Sayre syndrome (KSS) results in progressive loss of vision and hearing, as well as heart defects. What is the genetic basis for this disease?

Deletions occur in mtDNA, and the proportion of defective mtDNAs increases as the severity of the symptoms increases.

In a mixed infection experiment, the results of an h+r and hr+ cross are as follows. How far apart are these two genes?

Distance between two genes = Recombination frequency = (# recombinants / total # progenies) 100 Recombinants = minimum in # Parental progenies = maximum in # Distance between the genes = (12 + 12) / (12 + 12 + 42 + 34) 100 = (24 / 100) 100 = 24 mu = 24%

Molecular/structural oreintations (gradients) in an egg are thought to play a significant role in development. What is the origin of such gradients?

During formation of the egg, nutritional as well as informational molecules (RNAs) are placed in appropriate positions for the development of the embryo

Albinism, lack of pigmentation in humans, results from an autosomal recessive gene. Two parents with normal pigmentation have an albino child. What is the probability that their next two children will be albino? A) 1/4 B) 1/3 C) 1/2 D) 3/4 E) 1/16

E) 1/16

Albinism, lack of pigmentation in humans, results from an autosomal recessive gene (a). Two parents with normal pigmentation have an albino child. What is the probability that their next three children will be albino? A) 3/4 B) 0 C) 1/8 D) 1/4 E) 1/64

E) 1/64

The diploid chromosome number of an organism is usually represented as 2N. Humans have a diploid chromosome number of 46. What would be expected haploid chromosome number in a human? A) 92 B) 16 C) 12 D) 24 E)23

E)23

List three organisms that provide examples of organelle heredity.

Homo sapiens, Mirabilis jalapa, Chlamydomonas reinhardi

Maternal-effect patterns result when nuclear gene products controlled by the maternal genotype condition the egg and influence early development. Give two examples of maternal effects.

Ephestia pigmentation and coiling in Limnaea

Who was the student in Morgan's laboratory that first realized that the sequence of genes could be determined by Morgan's proposal that two genes located relatively close to each other are less likely to form chiasma between them than if the two genes were relatively far apart?

H. Sturtevant

How are reciprocal crosses used to identify cases of extrachromosomal inheritance? What criteria would one use to state that a particular mode of inheritance is extrachromosomal?

In cases of extrachromosomal inheritance, because the "maternal" contribution is more significant than the "paternal" contribution, the results are different from those expected from simple Mendelian inheritance. The traits of the offspring are more influenced by the "maternal" contribution.

Types of centromere locations

Metacentric, submetacentric, acrocentric, telocentric

What is an example of a mitochondrial mutation in bread mold?

Mitochondrial mutation in Neurospora crassa (Bread Mold) - Slow growing mutant strain, poky - Associated with impaired mitochondrial function - Mutation due to absence of several cytochrome proteins needed for electron transport

What is an example of a mitochondrial mutation in yeast?

Mitochondrial mutation studies with Saccharomyces cerevisiae (yeast) - Mutations named petite due to small size of colonies - Deficiency in cellular respiration - Mitochondria performs abnormal electron transport Two Types: Segregational petites - Small percent of mutations are result of nuclear mutations Neutral petites - Demonstrate cytoplasmic transmission - Lack mtDNA or lack portion of it - Mitochondria inherited by both parental cells

In what way do mitochondrial mutations influence phenotype?

Mitochondrial mutations affect the production of ATP generated through cellular respiration.

Experimental therapies can prevent transmission of mtDNA mutations to offspring. What are some examples of this kind of therapy?

Mitochondrial replacement therapy (MRT) or three-parent in vitro fertilization

What explanation is generally given for the lethality of monosomic individuals?

Monosomy may unmask recessive lethals that are tolerated in heterozygotes carrying the wild-type allele.

Mirabilis jalapa (four o'clock plant) is an example of what type of extranuclear inheritance?

Organelle Heredity -Plant has white, green, and variegated leaves - Mutation in DNA housed in chloroplast - Genetic defect eliminated green chlorophyll (light-absorbing pigment within chloroplasts)

The natural effect in Lymnaea is such that the genotype of the egg determines the direction of shell coiling regardless of the genotype of the offspring. Apparently, the cause of this spectacular maternal effect results from ________________.

Orientation of the spindle apparatus in early cleavage

cas genes code for a variety of proteins, including _______.

RNases

Molecular/structural orientations (gradients) in an egg are thought to play a significant role in development. What evidence indicates that the maternal genotype is involved in providing such gradients?

Results (non-Mendelian) indicate that the direction of shell coiling in snails is determined by the genotype of the mother, not the genotype of the zygote.

In what way do segregational petite mutations differ from neutral petites?

Segregational petites follow Mendelian inheritance as a result of the influence of nuclear genes; neutral petites, when crossed to wild type, produce only wild-type, normal-sized colonies.

Who discovered the first known cytoplasmic mutation?

Studies by Ruth Sager (1954) - Streptomycin resistance in Chlamydomonas - Differences in reciprocal crosses with susceptible strains - Trait passed through female parent

An example of organelle heredity involves pigmentation in Mirabilis jalapa. TRUE or FALSE

TRUE

Why is variegation in four o' clock plants determined by the phenotype of the ovule source?

The chloroplasts determine the leaf coloration and the chloroplasts are inherited through the ovule.

What is the meaning of the term endosymbiotic theory?

The endosymbiotic theory states that mitochondria and chloroplasts arose independently about 2 billion years ago from free-living protobacteria.

What is the expression pattern of dominant-negative mutations in petite strains of yeast?

The function of wild-type mitochondria is suppressed.

Which of the following scenarios would erroneously lead you to believe two genes reside on different chromosomes when they in fact are on the same chromosome?

The genes are very far apart on the same chromosome, such that there is always a crossover between them

A color-blind, chromatin-positive male child (one Barr body) has a maternal grandfather who was colorblind. The boy's mother and father are phenotypically normal. What needed to occur to have this genetic condition?

The mother must be heterozygous and underwent nondisjunction at meiosis II.

In Maternal Effect, which of the following is true?

The mother's genotype is the offspring's phenotype

Based on the classic experiments of Creighton and McClintock with maize, crossing over involves a physical exchange between chromatids. What particular chromosomal characteristic allowed their experiments to succeed?

a chromosome with a unique cytological marker

complementation group

a group of mutations that affect the same gene

What is the outcome of nondisjunction in meiosis I?

a resultant gamete that may harbor from one chromosome, both sister chromatids or none at all

Which of the following statements below is false? a. Normally in humans, all the sons of a male showing an X-linked phenotype will inherit the trait. b. At meiosis I, the X and Y chromosomes line up as if they were homologs. c. Normally in humans, females are carriers of X-linked recessive traits if they are heterozygous. d. Normally in humans, all the sons of a male showing an X-linked phenotype will inherit the trait. e. Normally in humans, a male that is carrying an X-linked dominant trait will pass it to all his daughters.

a. Normally in humans, all the sons of a male showing an X-linked phenotype will inherit the trait.

Which of the following statements is true? a. With both incomplete dominance and codominance, one expects heterozygous and homozygous classes to be phenotypically identical. b. An individual won't show incomplete dominance if one allele is a loss of function allele. c. The threshold affect is only seen in incomplete dominance, not in codominance. d. Even in a seemingly clear-cut example of complete dominance, at the protein or enzyme level, one can detect about half the activity or gene product. e. In the threshold effect, one would expect the gain of function mutant to be recessive.

a. With both incomplete dominance and codominance, one expects heterozygous and homozygous classes to be phenotypically identical.

Many of the color varieties of summer squash are determined by several interacting loci: AA or Aa gives white, aaBB or aaBb gives yellow, and aabb produces green. Crosses among heterozygotes give a 12:3:1 ratio. What type of gene interaction would account for these results? a. epistasis b. conditional lethal c. complementation d. multiple alleles e. incomplete dominance

a. epistasis

The trait of medium-sized leaves in iris is determined by the genetic condition PP'. Plants with large leaves are PP, whereas plants with small leaves are P'P'. A cross is made between two plants each with medium-sized leaves. What is the term for this allelic relationship? a. incomplete dominance b. codominance c. multiple alleles d. epistasis e. positional effect

a. incomplete dominance

Assume that a mutation occurs in the gene responsible for the production of hexosaminidase A, such that only about 50% of the enzyme activity is found in the heterozygote compared with a homozygous normal individual. If heterozygotes are phenotypically normal, we would say that the mutant allele is _______________ to its normal allele. a. recessive b. dominant c. gain of function d. epistatic e. auxotrophic

a. recessive

Through the study of mitochondrial disorders, scientists have suggested a link between the decline of mitochondrial function and aging. What process appears to be involved in this suspected phenomenon?

accumulation of mutations in the mtDNA

Assume that a man who carries an X-linked gene has children. Assuming normal meiosis and random combination of gametes, the man would pass this gene to ________.

all of his children

Doubling the chromosomes of a sterile species hybrid with colchicine or cold shock is a method used to produce a fertile species hybrid called a ______________________.

amphidiploid

The condition that exists when an organism gains or loses one or more chromosomes but not a complete haploid set is known as ________.

aneuploidy

________________ phenotypes are passed equally to offspring by both males and females.

autosomal dominant

Name the polylpoid condition that is formed from the addition of an extra set of chromosomes identical to the normal diploid complement of the same species.

autotetraploidy, assuming the normal chromosome complement is diploid

A snapdragon plant has red, pink, or white flowers, inherited in an incomplete dominance fashion. It's height is inherited in a dominant/recessive pattern. Tall is (T) and dwarf is homozygous recessive. What is the ratio when you cross pink-tall (Tt) with a pink-short (tt) plant? a) 1 red tall : 1 red dwarf: 2 pink tall: 2 pink dwarf: 1 white tall: 1 white dwarf b) 1 red tall: 1 red dwarf: 1 pink tall: 1 pink dwarf: 1 white tall: 1 white dwarf c) 3 red tall :3 red dwarf: 1 white tall: 1 white dwarf d) 2 red tall: 2 red dwarf: 1 pink dwarf: 1 white tall: 1 white dwarf e) 2 red tall: 1 red dwarf: 1 pink dwarf: 2 white tall: 1 white dwarf

b) 1 red tall: 1 red dwarf: 1 pink tall: 1 pink dwarf: 1 white tall: 1 white dwarf

In mitosis, cytokinesis is followed by karyokinesis. a) True b) False

b) False

In transcription, mRNA binds to ribosome and synthesizes protein. a) True b) False

b) False

Replication of DNA of each chromosome occurs during G1 of interphase. a) True b) False

b) False (during S phase!)

If the expression of a specific phenotype is limited to one sex, it is called sex-influenced inheritance. a) True b) False

b) False (sex-limited inheritance!)

When phenotypes are affected by more than one genes, it is known as a) Pleiotropy b) Gene interaction c) Haplosufficiency d) Penetrance e) Gene anticipation

b) Gene interaction

Prokaryotes share all of the following features with eukaryotes except a) Plasma membrane b) Membrane-bound organelle c) Ribosome d) DNA e) RNA

b) Membrane-bound organelle

Neutral mutation is referred to as a) Complete loss of function b) No detectable change in function c) Enhancement of function d) Detectable change in function e) None of the above

b) No detectable change in function

Typically, when one wishes to represent a gene, the symbol used is _________. a) in all upper case letters b) in italics c) in all lowercase letters d) in bold print e) underlined

b) in italics

Which RNA carries the genetic code for specific protein synthesis? a) rRNA b) mRNA c) tRNA d) sRNA e) pRNA

b) mRNA

The trait of medium-sized leaves in iris is determined by the genetic condition PP'. Plants with large leaves are PP, whereas plants with small leaves are P'P'. A cross is made between two plants each with medium-sized leaves. If they produce 80 seedlings, what would be the expected phenotypes, and in what numbers would they be expected? a. 10 (large leaves), 60 (medium leaves), 10 (small leaves) b. 20 (large leaves), 40 (medium leaves), 20 (small leaves) c. 20 (large leaves), 20 (medium leaves), 40 (small leaves) d. 40 (large leaves), 40 (medium leaves), 0 (small leaves) e. 40 (large leaves), 0 (medium leaves), 40 (small leaves)

b. 20 (large leaves), 40 (medium leaves), 20 (small leaves)

Rabbits can come in an allelic series where brown > himilayan > chinchilla > albino, where > means dominant over. They can also come in long (recessive) and short fur. You wish to obtain rabbit babies that are albino with long fur. Which of the following crosses would you do? a. albino with long fur x homozygous himilayan with short fur (heterozygote) b. chinchilla heterozygous with albino with short fur (heterozygous) x brown heterozygous with albino with long fur c. albino with long fur x albino with short fur (homozygous) d. albino with long fur x brown chinchilla heterozygote with long fur e. homozygous brown with long fur x albino with short fur (heterozygote)

b. chinchilla heterozygous with albino with short fur (heterozygous) x brown heterozygous with albino with long fur

A condition in which one gene pair masks the expression of a nonallelic gene pair is called ___________. a. codominance b. epistasis c. dominance d. recessiveness e. additive alleles

b. epistasis

Because of the mechanism of sex determination, males of many species can be neither homozygous or heterozygous. Such males are said to be ____________. a. dominant b. hemizygous c. recessive d. complementary e. none of the answers listed are correct

b. hemizygous

Which of the following matings indicates that a Chlamydomonas mutant with photosynthetic defects (that resulted from a deficiency in chloroplast translation) is located on the chloroplast genome? a. mt+ photo- x mt- photo+ b. mt+ photo+ x mt- photo- yields all str- c. mt+ photo- x mt- photo+ yields mt+ d. a petite x alpha wild type yields all petite

b. mt+ photo+ x mt- photo- yields all str-

Axis development is determined by a MATERNAL EFFECT gene in Drosophilia. A dominant Bicoid allele is required to set up the correct axis development in flies. bb (two loss of function alleles) is LETHAL in this MATERNAL EFFECT gene. A female Drosophilia named Eustacia had all dead offspring. What is Eustacia's genotype?

bb

Separation of sister chromatids of each chromosome known as disjunction occurs during which phase of mitosis? a) Prometaphase b) Metaphase c) Anaphase d) Telophase e) Interphase

c) Anaphase

All of the following are true for incomplete dominance except a) F1 generation express an intermediate phenotype b) Genotypic and phenotypic ratios are same in F2 generation c) Both alleles are dominant d) Each genotype has its own phenotype e) Tay-Sachs disease is an example of incomplete dominance in humans

c) Both alleles are dominant

The main event in the metaphase stage of mitosis is a) Chromosomes condense, centrioles divide and move apart b) Daughter chromosomes migrate to opposite poles c) Chromosomes align on equatorial plane d) Nuclear envelop begins to break e) Cytokinesis

c) Chromosomes align on equatorial plane

In autosomal dominant disorders a) Affected child may or may not have an affected parent b) Males are only affected c) Typically, do not skip generations d) Only females can transmit the disease e) All of the above are correct

c) Typically, do not skip generations

1) In many species, there are two representatives of each chromosome. In such species, the characteristic number of chromosomes is called..........., which is symbolized as ......... a) haploid, n b) haploid, 2n c) diploid, 2n d) diploid, n e) none of the above

c) diploid, 2n

Which of the following is true about X-linkage? a) one result of X-linkage is a crisscross pattern of inheritance in which sons express recessive genes of their fathers and daughters express recessive genes of their mothers b) one result of X-linkage is a crisscross pattern of inheritance in which daughters express recessive genes of their fathers and sons express recessive genes of their mothers c) males are more liable to express recessive alleles as they are hemizygous d) females will only express dominant alleles e) X linkage demonstrates that only the wild-type allele is dominant

c) males are more liable to express recessive alleles as they are hemizygous

With incomplete dominance, a likely ratio resulting from a monohybrid cross would be ___________. a. 3:3 b. 1:2:2:4 c. 1:2:1 d. 9:3:3:1 e. 3:1

c. 1:2:1

Typical ratios resulting from epistatic interactions in dihybrid crosses would be _________________. a. 9:3:3:1, 1:2:1 b. 1:1:1:1, 1:4:6:4:1 c. 9:3:4, 9:7 d. 1:2:2:4:1:2:1:2:1, 1:2:1 e. 3:1, 1:1

c. 9:3:4, 9:7

What is a significant difference between X-linked and sex-influenced inheritances? a. There are no differences. They are the same. b. X-linked inheritance affects females and sex-influences inheritance affects males. c. In X-linked inheritance, the gene in question is on the X chromosome; in sex-influenced inheritance, the gene is autosomal. d. Sex-influenced inheritance requires epistasis, X-linked inheritance does not. e. X-limited inheritance is only recessive. Sex-influenced inheritance can be recessive or dominant

c. In X-linked inheritance, the gene in question is on the X chromosome; in sex-influenced inheritance, the gene is autosomal.

Which of the following is an example of sex-limited inheritance? a. human baldness b. cat fur length c. beard formation in humans d. hemophilia e. hair color in humans

c. beard formation in humans

An example of __________________ involves pigmentation in Mirabilis jalapa. a. nuclear inheritance b. gene dosage effect c. organelle heredity d. maternal effect e. X-linked recessive

c. organelle heredity

Examples of modifications to Cas9 include all of the following except ____________________. a.epigenetic modifiers b.fluorescent proteins c. promoter domains d. repression domains

c. promoter domains ?

Which of the following is an example of an endopolylpoid?

cells lining the gut of mosquito larvae attain 16n ploidy

To which of the following does the term heteroplasmy refer?

cells with a variable mixture of normal and abnormal organelles

In E. coli, the genetic material is composed of __________________.

circular, double-stranded DNA

Multiple mutations that are found to be present in a single gene are said to belong to the same __________ group. a. phenotypic b. allelic c. transfer d. complementation e. expression

complementation group

Jacob, Wollman, and others developed a linkage map of E. coli that is based on time. What form of recombination is involved in generating a linkage map based on time?

conjugation

What is a form of recombination in bacteria that involves the F plasmid?

conjugation

Once an exogenous (foreign) piece of DNA is in the bacterial cell, it is incorporated into the bacterial genome through....

crossing-over (recombination)

The plant coleus has three distinct leaf color phenotypes: green, white, and variegated (white & green mixed) the crosses are made as follows: female variegated leaves x male green leaves gives offspring with all variegated leaves female green leaves x male with white leaves gives offspring with all green leaves female with white leaves x male with variegated leaves gives offspring with all white leaves This is an example of ________________.

cytoplasmic inheritance (Maternal effect is a result of mRNA and proteins (gene products) received from the cytoplasm of the mothers' egg. Cytoplasmic inheritance is a result of genetic material in the mitochondria or chloroplasts or infective viruses. This is the main difference between cytoplasmic inheritance and genetic maternal effect.)

Which statement about RNA is correct? a) It is double-stranded, contains ribose as sugar and uracil in place of thymine b) It is single-stranded, contains ribose as sugar and thymine in place of uracil c) It is double-stranded, contains deoxyribose as sugar and thymine in place of uracil d) It is single-stranded, contains ribose as sugar and uracil in place of thymine e) It is single-stranded, contains deoxyribose as sugar and uracil in place of thymine

d) It is single-stranded, contains ribose as sugar and uracil in place of thymine

What is the outcome of synapsis? a) side-by-side alignment of nonhomologous chromosomes b) dyad formation c) monad movement to opposite poles d) side-by-side alignment of homologous chromosomes e) chiasma segregation

d) side-by-side alignment of homologous chromosomes

The deficiency of the enzyme glucose-6-phosphate dehydrogenase (G6PD) is inherited as a recessive gene on the X chromosome in humans. A phenotypically normal woman (whose father had G6PD) is married to a normal man. What fraction of their sons would be expected to have G6PD? a. zero b. 1/3 c. 1/4 d. 1/2 e. 100%

d. 1/2

Which of the following statements is false? a. an individual with Klinefelter syndrome generally has one Barr body b. An individual with Turner Syndrome has no Barr bodies c. A typical XX female has one Barr body d. Dosage compensation is accomplished in humans by inactivation of the Y chromosome. e. In a cell with X chromosomes lacking the XIC, there is stillX inactivation

d. Dosage compensation is accomplished in humans by inactivation of the Y chromosome.

With which of the following would hemizygosity most likely be associated? a. codominance b. incomplete dominance c. trihybrid cross d. X-linked inheritance e. sex-limited inheritance

d. X-linked inheritance

All of the following are challenges in gene therapy EXCEPT.... a. unkown specific mutations b. inaccessible tissues c. unknown cell types d.designing a strategy

d.designing a strategy

What is a physical map of chromosome?

description of the base pair difference between two loci

In mice, there is a set of multiple alleles of a gene for coat color. Four of those alleles are as follows: C = full color cch = chinchilla cd = dilution c = albino Given that the gene locus is not sex-linked and that each allele is dominant to those lower in the list, give the phenotypic ratios expected from the following cross: chinchilla (heterozygous for albino) x albino a. 1 dilution : 1 chinchilla : 1 albino b. 1 full color : 1 chinchilla : 1 albino c. 2 chinchilla : 1 albino d. 1 chinchilla : 2 albino e. 1 chinchilla : 1 albino

e. 1 chinchilla : 1 albino

Assume that a dihybrid cross (AaBb xAaBb) is made in which the gene loci are autosomal, independently assorting, and incompletely dominant. What phenotypic ratio would you expect from such a cross? a. 1:2:2:1:4:2:1:2:1 b. 2:1:1:2:2:1:4:2:2 c. 1:2:1:2:2:2:1:4:1 d. 2:2:2:2:2:2:2:2 e. 1:2:1:2:4:2:1:2:1

e. 1:2:1:2:4:2:1:2:1

A mutation in a gene often results in a reduction of the product of that gene. The term for this type of mutation is _______________. a. codominance b. incomplete dominance c. gain of function d. multiple allelism e. loss of function or null (in the case of complete loss)

e. loss of function or null (in the case of complete loss)

With ____________, there will be more than two genetic alternatives for a given locus. a. codominance b. gain of function mutant c. incomplete dominance d. epistasis e. multiple alleles

e. multiple alleles

Which criterion below does not indicate that a human disorder may be attributable to genetically altered mitochondria? a. maternal rather than Mendelian inheritance pattern b. deficiency in some bioenergetic functions of mitochondria c. documentation of a specific mitochondrial genetic mutation d. deficiency in ability to generate ATP e. passed down more readily to male offspring

e. passed down more readily to male offspring

Which of the following crosses would indicate that the mutants were in the same complementation group? a. pink eye fly x white eye fly -> all white eyes b. pink eye fly x pink eye fly -> all white eye offspring c. red eye fly x red eye fly -> 3:1 ratio d. pink eye fly x pink eye fly -> purple eye flies e. pink eye fly x pink eye fly -> pink eye fly

e. pink eye fly x pink eye fly -> pink eye fly

Which of the following is not a potential outcome of a gene duplication? a. they may result in gene redudndancy b. they may result in providing the raw material for evolution c. they may produce phenotypic variation d. they may lead to the development of gene families e. they may lead to translocation cross formation during synapsis

e. they may lead to translocation cross formation during synapsis

If two different auxotrophic strains are placed in a liquid medium culture tube, prototrophic strains can sometimes be subsequently recovered. Choose the mechanism below that would not allow this genetic change. a. reverse mutation b. genetic suppression c. conjugation d. transformation e. transduction

e. transduction (involves bacteriophages)

Chromatin of eukaryotes is organized into repeating interactions with protein octomers called nucleosomes. Nucleosomes are composed of which class of molecules?

histones

Assume that a cross is made between AaBb and aabb plants and that the offspring fall into approximately equal numbers of the following groups: AaBb, Aabb, aaBb, aabb. These results are consistent with which of the following?

independent assortment

Researchers in the late 1950s isolated multiple antibiotic-resistant strains of the bacterium Shigella, which causes dysentery. Such resistance was caused by nonchromosomal R factors that originated in E. coli. Which of the following forms of extrachromosomal heredity-maternal effect, organelle heredity, infectious heredity-would you consider most closely related to the transfer bacterial antibiotic-resistant strains?

infectious heredity

What is the name of a form of extrachromosomal inheritance that is due to transmission of symbiotic or parasitic microorganisms?

infectious heredity

A situation in which there are more than two alternative forms of a given gene would be called ______________. a. multiple alleles b. alternation of generations c. codominance d. incomplete dominance e. hemizygosity

multiple alleles

Name two human disorders that appear to be transmitted extrachromosomally

myoclonic epilepsy and ragged red fiber disease

A child is born with Turner's syndrome and she is red green color blind (recessive X-linked). Her father is red green color blind as well and her mother is homozygous dominant for color sight. What had to happen in order for this child to be born with this chromosomal complement?

non-disjunction in either meiosis I or meiosis II of the mother

Majority of proteins for mitochondrial function are encoded by ____________________.

nuclear genes - DNA and RNA polymerase - Initiation and elongation factors - Ribosomal proteins - Aminoacyl tRNA synthetases

Inheritance of the green and white patches phenotype in Mirabilis jalapa (four o' clock) is an example of _________________.

organelle heredity

In aerobically cultured yeast, you isolate a petite mutant. You believe it is a suppressive mutant. Which cross would you do below to determine that it is indeed suppressive?

petite x wild type yields all petites

________________ occurs when a crossover in one region of a chromosome reduces crossovers in nearby regions.

positive interference

Which three classes of macromolecules are encoded by mtDNA?

proteins, transfer RNAs, and ribosomal RNA

The primary value of the CRISPR-Cas system in biotechnology is __________________.

rapid and cost-effective production of genetically modified organisms

Assume that investigators crossed a strain of flies carrying the dominant eye mutation Lobe on the second chromosome with a strain homozygous for the second chromosome recessive mutations smooth abdomen and straw body. The F1 Lobe females were then backcrossed with homozygous smooth abdomen, straw body males, and the following phenotypes were observed: smooth abdomen, straw body 820 Lobe 780 smooth abdomen, Lobe 42 straw body 58 smooth abdomen 148 Lobe, straw body 152 Give the gene order and map units between these three loci.

smooth abdomen --- 5 cM ----- lobe ----- 15 cM ----- straw body COC = zero

Which of the following is the correct order of steps for the CRISPR-Cas mechanism?

spacer acquistion, biogenesis, target interference

What relatively recent scientific advancement has made mapping by linkage or classical genetic mapping approaches virtually obsolete?

the genome sequence of a species

Gene amplification is the basis for ___________________________.

the nucleolar organizing region

Type II CRISPR-Cas systems are the most widely used systems because...

they only require a single protein, Cas9 ?

A form of bacterial recombination that involves a viral intermediate called __________________________.

transduction

Genetic anticipation is best described as....

trinucleotide repeats increase in future generations

An expected meiotic pairing configuration in a ________________ would be a trivalent.

triploid

Assume that a species has a diploid chromosome number of 24. The term applied to an individual with 25 chromosomes would be ____________________.

triploid

Assume that a species has a diploid chromosome number of 24. The term applied to an individual with 25 chromosomes would be...

triploid

Inversion heterokaryotypes are often characterized as having reduced crossing over and reduced fertilty. Assume that you were examoining a strain of organisms you knew to be inversion heterokaryotypes and saw a relatively high number of double chromatid bridges extending between anaphase I nuclei, as indicated in the following drawing. What is the product of this type of inversion loop?

two acentric fragments and two dicentric fragments